The Ontario Immunization of School Pupils Act states that children attending school in Ontario must be vaccinated against diphtheria, measles, mumps, poliomyelitis, rubella and tetanus, pertussis, meningococcal serotype C, and varicella or have a valid exemption. Exemptions may be for rare medical reasons identified by a physician or a personal decision notarized by a Commissioner of Oaths. This Act exists to protect the health of individuals and groups.
Vaccine coverage is the percentage of individuals in a specified group who are fully vaccinated against a certain disease. High vaccine coverage leads to herd immunity, which protects us all.
The Routine Childhood Vaccine Coverage section contains the following pages:
For information on influenza coverage, please go to our influenza vaccine coverage section.
Herd Immunity:
When enough people are immunized against a disease, it is very difficult for that disease to spread to those who are not immune. This is known as ‘herd immunity’. Since no vaccine is 100% effective, it is essential that as many people as possible get immunized not only to protect themselves but also to protect others. Those who choose not to immunize are risking the health of not only their children, but also the health of children who cannot be immunized due to illnesses, allergies, or age (less than one year), and those who were immunized but did not develop immunity.
In Canada, the national coverage target is 95% for diphtheria, tetanus, polio, measles, mumps and rubella. This means that 95% of the population should be immunized against these diseases for optimal protection of the population against these diseases. The targets are to be achieved by 2025.
Herd Immunity Explained:
Source: Immunize BC and Health Canada.
The figure below depicts the outcomes when people do not get immunized (top), versus when people do get immunized (bottom).

Source: U.S. National Institute of Allergy and Infectious Diseases
Reporting Immunization Information:
The Immunization of School Pupils Act also requires the health unit to keep immunization records for children attending Simcoe Muskoka schools. This information is crucial to preventing further spread when there is a case of a vaccine preventable disease in a school. Unvaccinated children may be excluded from school for a period of time to help protect them and prevent a larger outbreak.
In order for the health unit to maintain accurate records, parents of school-aged children must notify the health unit every time their child is immunized by anyone other than health unit. Children can be suspended from school for not providing the health unit with up to date information. For more information on how to report, see the health unit website on reporting immunization information.
For the number of vaccine preventable diseases in Simcoe Muskoka, see the HealthSTATS page on the incidence of diseases preventable by routine childhood immunization.